Entry columns not saving

Entry columns not saving.
Wanted to add a column to the ‘active’ columns from 'inactive. Allowed me to move one accross but will not save! Does not ‘popup’, just goes to new screen (see screenshots) and does not save. and no way back to entries.
Any ideas?!(upload://wirPyOLjaEO6ZLelIC8JHfQR0Zv.jpeg)

I recommend opening a support ticket for this issue:


It’s most likely a theme or plugin conflict. You can check for conflicts first by using these steps: